Zerstörungsfreie Charakterisierung der Degradation von ... · Zerstörungsfreie Charakterisierung...

Center for Nondestructive Evaluation

Zerstörungsfreie Charakterisierung der Degradation von Werkstoffen und Bauteilen im

Einsatz

Nach wie vor eine Herausforderung für konventionelle und moderne Werkstoffe zur Anwendung im Leichtbau

Norbert Meyendorf

Center for Nondestructive Evaluation2

de Havilland CometBOAC Flight 781 and South African Airways Flight 201

Two de Havilland Comet passenger jets broke up in mid-air and crashed within a few months of each other in 1954. As a result, systematic tests were conducted on a fuselage immersed and pressurized in a water tank. After the equivalent of 3,000 flights investigators at the Royal Aircraft Establishment (RAE) were able to conclude that the crash had been due to failure of the pressure cabin at the forward Automatic Direction Finder window in the roof. This 'window' was in fact one of two apertures for the aerials of an electronic navigation system in which opaque fiberglass panels took the place of the window 'glass'. The failure was a result of metal fatigue caused by the repeated pressurization and de-pressurization of the aircraft cabin.

CC BY‐SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2088812


Damage Airbus Cracks

Airbus orders more frequent A380 wing inspections due to fatigue checks

Europe's Airbus (AIR.PA) has ordered more frequent inspections of the wings of the world's largest passenger jet after discovering unexpected levels of metal fatigue during testing on an A380 factory mock-up, industry sources said on Thursday.

http://www.reuters.com/article/us-airbus-group-a-idUSBREA252DE20140306Business | Thu Mar 6, 2014 5:42pm ESTRelated: Aerospace & Defense


Airbus A380 Full Scale Fatigue Test

Schwarberg, IABG Dresden


New MaterialsThe introduction of new materials and technologies requires a multitude of investigations and verifications known as testing pyramid starting with coupons and components to complete aircraft structures. Static and dynamic properties are examined

© Rainer Franke | DGM-DIALOG 2011 | 16.06.2011 | 3

Coupon test Panel test Barrel test Full scale fatigue testCurved Panel test


Why this is not sufficient

• Complex design• Material inhomogeneity• Test conditions versus real load cycles• Temperature effect • Materials scatter • Microstructure changes during service• Aging


Things Effecting Fatigue Damage

• Internal defects / stress concentrators• Interaction with other effects• Corrosion • Creep• Change of material properties due to

service load• ……


Understanding the Widespread FatigueWWW.boeing.com/BoeingEdge/aerom

AERO_2012q4_article2.pdfagazineNew Damage Rule

The development of widespread fatigue damage (WFD) in airplane structure is a concern for older airplanes. The U.S. Federal Aviation Administration (FAA ) has published a rule that will limit the commercial usage of older airplanes, requiring service actions to preclude the onset of WFD and retirement.By Amos W. Hoggard, Technical Fellow (Retired), Aging Airplane SafetyRule/Widespread Fatigue Damage Program, andStephen R. Johnson, Aging Airplane Safety Rule/Widespread Fatigue DamageProgram Manager, Chief Structures Engineer

What happens if the material properties change during service due to service conditions???


WB 36 — fracture toughness at crack initiation.

Example from Nuclear Industry


Results of a Monte Carlo simulation on formation and growth of copper precipitates; only the copper, not the iron atomsare shown.

Cross-section through the iron structure model used for the nano-simulation of the dislocation movement; scale in 1Å, (0.1nm).

WB 36 — size distribution of the copper precipitates.

Example from Nuclear Industry


2L

PINNING POINTS

MIDDLE PRECIPITATE

Interaction of precipitates with dislocation

Fine phase precipitates Coarse phase precipitatesReference: Edited by J. Hatch, Aluminum: Properties and Physical Metallurgy, American Society for Metals, 1984, p145

Reference: S. Kuhr, A Microstructural Characterization of Aluminum 7075-T6 Treated with the Retrogression and Re-Aging Process

Precipitations in AA 7075-T6

© Fraunhofer IZFP-D

Annihilation parameters depend on• Chemical composition of the alloy• Defects (point defects, dislocations coherent /incoherent precepitations)

Quant (511 keV)

Quant (1.27 MeV)

Positron Annihilation Technique

© Fraunhofer IZFP-D

Aging of Aluminium Alloys: Positron Lifetime Data

• Exponential change of positron lifetime

• Change in chemical composition and microstructure (GP2 zones)

219217

215

10 100 1000

200

198

196

194

192

190

200

198

196

194

192

190

1 10

219

217

215

0 2

Average Lifetime Linear fit

Artificial Aging at 85°CAl 2024

Time [h]

Time [days]

Aver

age

lifet

ime

[ps]

210

205

200

195

190

103

104

105

Time [h]

210

205

200

195

190

0.1 1 10Time [years]

Aver

age

lifet

ime

[ps]

Avarage Lifetime Linear fit

Natural Aging at RTAl 2024

T. E. M. Staab, E. Zschech, R. Krause-Rehberg, J. Mater. Sci. 35, 4667 (2000)

Increase of Cu content in GP zones => positron lifetime decreases


Airbus Identifies ‘Cracking Behavior’ in A400M Military AircraftAndrea Rothman May 14, 2016 — 1:00 AM CEST

http://www.bloomberg.com/news/articles/2016-05-13/airbus-identifies-cracking-behavior-in-a 400m-military-aircraft

“As part of the normal quality control processes in the A400M fleet we have identified a material issue,” Airbus said in a statement late Friday. “It concerns a previously unknown cracking behavior of an aluminum alloys material. The issue is not impacting flight safety and does not require any immediate measures beyond a program of inspections and repairs that can be incorporated into the normal maintenance and upgrades schedules.”


That is behind the Cracks in the Airbus FuselageDas steckt hinter den Rissen im Airbus-Rumpf,

Die Welt 26.04.16

• Already in 2011 an AL Zn alloy showed an unknown material behavior. First indication during full scale fatigue test in Dresden

Hinter den Kulissen gibt es aber Aufregung um die Abläufe. So räumt die für den A400M-Bau verantwortliche Rüstungs- und Sicherheitssparte ein, dass bereits 2011 eine Aluminium-Legierung "ein vorher unbekanntes Materialverhalten" zeigte. Da hatte das erste A400M-Modell schon längst seinen Erstflug. In Branchenkreisen ist zu hören, dass 2011 die Auffälligkeiten bei Bauteilen aus modernen Aluminium-Zink-Legierungen bei einem Zeitraffer-Belastungstest am Boden auffielen. Dabei wurde bei einer A400M in einer Testhalle in Dresden ein komplettes Flugzeugleben simuliert.

• The material was approved for application since 2008 Die Experten standen vor einem Rätsel, zumal das Material der Alu-Legierung bereits seit 2008 für den Einsatz zugelassen war. Daher begannen auch ab Herbst 2013 die A400M-Auslieferungen, zuerst an Frankreich. Eingekreist wurde die Risse-Ursache erst zwei Jahre nach dem Belastungstests in Airbus-Laboren in einer ersten Ursachenvermutung.

• Explanation in 2015: Mixture of chemical composition, pressure, stress, temperature (service conditions). It is not corrosion!

Nach weiteren Forschungen und Tests gelang es 2015, eine Erklärung herauszufiltern. Die Rede ist von einem komplexen Mix aus der chemischen Zusammensetzung der Alu-Zink-Legierung und anderen Faktoren wie Druck, Dehnung und Temperatur, kurz Umwelteinflüssen. Laut Airbus handelt es sich nicht um Korrosion.

• The AL Zn alloy will also be used for A 350Im Fokus stehe der Rumpfabschnitt, der die Belastungen der Tragflächen aushalten muss. Bislang sind gut zwei Dutzend A400M-Modelle ausgeliefert. In Luftfahrtkreisen ist zu hören, dass Bauteile aus der umstrittenen Aluminium-Zink-Legierung auch beim neuen Langstreckenmodell A350 zum Einsatz kommen – allerdings im kleinen Maßstab.

• For insiders the A400M material fiasco is a proof for risks (that might result) from the competition for new aircraft materials

Für Branchenkenner ist das A400M-Materialdebakel ein Beleg für die Risiken aus dem Wettbewerb um neue Flugzeugwerkstoffe. Auf der einen Seite stehen die großen Hersteller von Aluminium-Legierungen, wie Alcoa (USA) oder Constellium (Niederlande), die Angst um ihr Geschäft haben, seitdem hochfeste und leichte Kohlefaserwerkstoffe (CFK) in den Flugzeugbau Einzug halten.


The Material?

EN AW-7030 ; Al Zn5.5Mg1Cu???

• Well known as: Al Zn5.5Mg1Cu AA7075• Can be compared but has higher Copper content• General 7075 characteristics and uses (from Alcoa):The T7351

temper (can be compared to RRA) offers high strength and improved stress-corrosion cracking resistance.

• Applications: Aircraft fittings, gears and shafts, fuse parts, meter shafts and gears, missile parts, regulating valve parts, worm gears, keys, aircraft, aerospace and defense applications; bike frames, all terrain vehicle (ATV) sprockets.

• Mechanical properties and SCC are very sensitive to heat treatment.


Images of material after 40 minutes RRA time.

2040

60

Grain boundary Precipitates

Coarse PrecipitatesFine Precipitates

0

0.2

0.4

0.6

0.8

1

RRA time (min)

NormalizedAvg.Diameter

Average diameter of precipitations form TEM experiment

Retrogression and Re-Aging of AA 7075-6

Meyendorf N., Sathish S., Ananthula R., Siddoju A., Kuhr S.Retrogression and Re-Aging (RRA) of 7075-T6 Corrosion Prone Parts; Part: Nondestructive Microstructure Characterization, Delivery Order No. F42620-00-D-0039


Scan size 800 nm, transducer frequency 478.3 kHz

NDE of Precipitations in AA 7075

Sample

Tip

Water layer

Stress field

3a

Static force F

Contact radius

aR

R ~ 30 nm – 200 nma ~ 5 nm – 20 nm

US-transducer f ~ cantilever-frequency



NDE of Precipitations in AA 7075



Conclusion

• New high tech materials might change their designed properties due to service conditions

• Usually modeling and lab tests do not consider these effects

• NDE or continuous monitoring (SHM) will be required even if no fatigue is predicted by the designers of the structure


Accidents by fatigue• Others• The 1862 Hartley Colliery Disaster was caused by the fracture of a steam engine beam and killed 220 people.• The 1919 Great Molasses Flood has been attributed to a fatigue failure.• The 1948 Northwest Airlines Flight 421 crash due to fatigue failure in a wing spar root• The 1957 "Mt. Pinatubo", presidential plane of Philippine President Ramon Magsaysay, crashed due to engine failure

caused by metal fatigue.• The 1965 capsize of the UK's first offshore oil platform, the Sea Gem, was due to fatigue in part of the suspension system

linking the hull to the legs.• The 1968 Los Angeles Airways Flight 417 lost one of its main rotor blades due to fatigue failure.• The 1968 MacRobertson Miller Airlines Flight 1750 that lost a wing due to improper maintenance leading to fatigue failure• The 1977 Dan-Air Boeing 707 crash caused by fatigue failure resulting in the loss of the right horizontal stabilizer• The 1980 LOT Flight 7 that crashed due to fatigue in an engine turbine shaft resulting in engine disintegration leading to

loss of control• The 1985 Japan Airlines Flight 123 crashed after the aircraft lost its vertical stabilizer due to faulty repairs on the rear

bulkhead.• The 1988 Aloha Airlines Flight 243 suffered an explosive decompression due to fatigue failure.• The 1989 United Airlines Flight 232 lost its tail engine due to fatigue failure in a fan disk hub.• The 1992 El Al Flight 1862 lost both engines on its right-wing due to fatigue failure in the pylon mounting of the #3 Engine.• The 1998 Eschede train disaster was caused by fatigue failure of a single composite wheel.• The 2000 Hatfield rail crash was likely caused by rolling contact fatigue.• The 2002 China Airlines Flight 611 had disintegrated in-flight due to fatigue failure.• The 2005 Chalk's Ocean Airways Flight 101 lost its right wing due to fatigue failure brought about by inadequate

maintenance practices.• The 2009 Viareggio train derailment due to fatigue failure.


Viareggio train derailmenthttps://en.wikipedia.org/wiki/Viareggio_train_derailment

The failure of an axle on the wagon that derailed is being investigated as a possible cause.[13][19] Italian Transport Minister Altero Matteoli informed the Italian Parliament on 1 July that a defective axle may have caused the accident.[16]


Ref: www.rheinzeitung.de

Crack in wheel rim

ICE Accident, June 3, 1998 Eschede

High speed train accident in Eschede101 people died


Source: DDP

ICE 518, July 9, 2008 Cologne

As a consequence to this event. Deutsche Bahn has significantly reduced the intervals for axle inspectionsfrom 250 000 to 60 000 km.


Impact of Information on our Business (»Bad News are good News«)

(Foto: 9.7.2008 – KStA)

ICE 518 Main Station ColonEschede, 3. June 1998


Why is this happening??

Material Properties are known Loading conditions are knownModelling of the structure is doneTesting for all structural dimensions performed

Usually coincidence of undetected defect(s) (inclusion, pores) and cyclic loading


Early Detection of Fatigue NDE

• Macroscopic Cracks

• Stress concentrators

• Microstructure effects/ Precipitations, dislocations, lattice defects

• Microstructure effects /Phase Transformations

• Microcracks

• Mesostructure????


NDE for Railroad Axels and Wheels

Required sequence of inspection cycles

Deutsche Bahn has significantly reduced the intervals for axle inspections from 250,000 to 60,000 km as a consequence of the Accident in Cologne

On Train Wheel set inspection system

Mobile Hollow Axle Testing System


Early Detection of Fatigue NDEMacroscopic Cracks• only at the end of life, • usually start from the surface• Techniques: Visual, Eddy Current, Ultrasound, Optics Stress concentrators • Technique: Thermoelastic effect, “Spate”

Microstructure effects/ Precipitations, dislocations, lattice defects

Microstructure effects /Phase Transformations

Microcracks

Mesostructure????


Thermoelastic Effect DeltaTherm 1000 image of the stresses in a chain link loaded at 10Hz. Image acquisition time: 30s. Courtesy Stress Photonics, Madison, WI.

T

t

TT0

t


Early Detection of Fatigue NDEMacroscopic Cracks• only at the end of life, • usually start form the surface• Techniques: Visual, Eddy Current, Ultrasound, Optics Stress concentrators • Technique: Thermoelastic effect, “Spate”Microstructure effects/ Precipitations, dislocations, lattice defects• Techniques: Internal damping, Heat dissipation (thermography), Electric conductivity,

Ultrasonic absorption, Nonlinear ultrasound, Positron annihilation Microstructure effects /Phase Transformations

Microcracks

Mesostructure????


Temperature Due to Mechanical Loading & Evaluation of The Initial Slope

t

T

T*diss= Tdiss - Tloss

Initial Slope

2· Tel

Stage 1

0

Stage 2 Stage 3

ft

Tdiss

diss

Tloss

Tdiss

(t)∆T(t)∆T(t)∆T T- T(t) ∆T(t) lossdissel0

diss

qdiss = c m diss

’ = qdiss/ 2 Wmax


0

2

4

6

0 2 5 .0 0 0 5 0 .0 0 0 7 5 .0 0 0

N [c y c le s ]

d

iss [

mK

]

F ra c tu re a t N f = 7 6 ,1 3 7

FATIGUE Ti-6Al-V4 LOW FREQUNCY EXCITATION

Mechanical Loading Power Ultrasonics Nonlinear AcousticsLoading frequency 30 Hz 20 kHz 10 MHzMax. Stress 500 MPa 50 MPa 0.5 MPa


Dislocation / phononinteraction

prop. L4

formation of dislocationnetwork reduces freedislocation length L andmodifies process

’

Damping by point defects

Oscillating dislocationspinned by point defectsgrain boundaries ...

’ - ’0 prop. diss diss0 prop. Dependence ofconcentration ofpinning points andTemperature expected

’

Moving dislocationsLocal plastic deformation

’0

Plastic strain

Specimen elongation

diss =a*am+1

m: Ramberg-Osgood Exponent

N N N

MEASUREMENT OF INTERNAL DAMPING30 Hz 20 kHz 10 MHz


Early Detection of Fatigue NDEMacroscopic Cracks• only at the end of life, • usually start form the surface• Techniques: Visual, Eddy Current, Ultrasound, Optics Stress concentrators• Techniques: Thermoelastic effect, “Spate”Microstructure effects/ Precipitations, dislocations, lattice defects• Techniques: Internal damping, Heat dissipation (thermography), Electric conductivity,

Ultrasonic absorption, Nonlinear ultrasound, Positron annihilation, Microstructure effects /Phase Transformations• Formation of ferromagnetic martensitic phases in austenite• Techniques: Ultrasonic damping, Permeability measurement (Ferritoscope, Squid,

Eddy Current)Microcracks• preferred for ductile materials• Techniques: Replica, Optics, Ultrasound Microscopy, Nonlinear Ultrasound???Mesostructure????


500 nm 500 nm 500 nm

0.00E+00

2.00E-05

4.00E-05

6.00E-05

8.00E-05

1.00E-04

1.20E-04

0 5 10 15 20 25 30 35Cycles x 10^3 (N)

Dis

loca

tion

Den

sity

(nm

-2)

Ti-6Al-4VX6 CrNiNb 18 10

COMPARISON OF MATERIALS

Source:Volker Schloß: Martensitic Transformation of Austenitic Steinless Steels, Microstructure Changes, and Possibilities of Early Detection of Fatigue Damage. PhD Thesis, Freiburg 2001


0102030405060708090

100

30 40 50 60 70 80 90 100Used life [%]

Microcrackspermm2

HF SAM

[S. Fassbender IZFP Report unpublished]

Number of cycles

Length ofsingle crack[mm]

Replica technique

Largest (micro) crack causes failure

[M.SESTER et all. IWM Report T 12/2000]

Micro crack growth during Fatigue ofX6 CrNiNb 18 10


Cra

ck le

ngth

Consumed Fatigue Life

Ti-6Al-4V

X6 CrNiNb 18 10

Limit for NDE Detection

0 100 %

Dis

loca

tion

dens

ity

Formation of subgrains

X6 CrNiNb 18 10Ti-6Al-4V

COMPARISON OF MATERIALS


Early Detection of Fatigue NDEMacroscopic Cracks• only at the end of life, • usually start form the surface• Techniques: Visual, Eddy Current, Ultrasound, Optics Stress concentrators• Techniques: Thermoelastic effect, “Spate”Microstructure effects/ Precipitations, dislocations, lattice defects• Techniques: Internal damping, Heat dissipation (thermography), Electric conductivity,

Ultrasonic absorption, Nonlinear ultrasound, Positron annihilation, Microstructure effects /Phase Transformations• Formation of ferromagnetic martensitic phases in austenite• Techniques: Ultrasonic damping, Permeability measurement (Ferritoscope, Squid,

Eddy Current)Microcracks• preferred for ductile materials• Techniques: Replica, Optics, Ultrasound Microscopy, Nonlinear Ultrasound???Mesostructure???? • Techniques: Fractal analysis of date from different imaging techniques


Fractal Dimension (DF)

A fractal is "a rough or fragmented geometric shape that can be split into parts, each of which is (at least approximately) a reduced-size copy of the whole," a property called self-similarity. Roots of mathematical interest on fractals can be traced back to the late 19th Century; however, the term "fractal" was coined by Benoît Mandelbrot in 1975 and was derived from the Latin fractus meaning "broken" or "fractured“. A mathematical fractal is based on an equation that undergoes iteration, a form of feedback based on recursion.

Fractal DimensionThe fractal dimension, D, is a statistical quantity that gives an indication of how completely a fractal appears to fill space, as one zooms down to finer and finer scales. Source: Wikipedia


Phenomena of Material Fatigue

What happens in the material?

source: H. Mughrabi, F. Ackermann: »Persistent slip bands in fatigued face centered and body centered cubic metals«

Micro level Macro level

Dislocations:GND – geometrical necessary IND – interface networkCells (Mughrabi, 83) Continuum mechanics

Mini cracks, fatal crack Fracture mechanicsSlip bands

Conventional Approach


Mesoscopic Deformation Structures

N - cycles number , NB - number of the cycles till the sample break

Juergen Schreiber1,Ulana Cikalova1, Andrey Bulavinov², Sandra Dugan³, Hans-Peter Maier³,Reactor Safety Research: Public Project 129 925 , »Evaluation of the materials fatigue and the residual lifetime of industrial components by the scaling behavior of noise signals - Fractal analysis II «

Scale levels of shear stability loss in deformed solid


0.5 mm

10 µm

36°

(111)-surface

10°

20°

Non-oriented FeSi Sheet


0

1

2

3

4

5

6

8

10

12

-4

-2

0

2

4

RMS

Y-Ach

se [c

m]

X-Achse [cm]

Barkhausen Map of Fatigued CT Sample22 NiMoCr 37

0

1

2

3

4

5

1.1

1.2

1.3

1.4

1.5

-4

-2

0

2

4

Fractal dimension D

F

Y-Ach

se [c

m]

X-Achse [cm]

RMS ~ Residual Stress Fractal Dimension

Crack


Fatigue in Composite Materials

• In metals the nucleation and growth of damage is well understood.

• Many decades of experience exist

• For composite materials damage nucleation and growth is still a matter of research

• Practical experience for material behavior under service conditions is limited

• For these materials NDE Techniques can help to examine degradation processes

Center for Nondestructive Evaluation46 46

inclusion and wrinkle

Common Composite Defects

matrix crack, broken fibers, debonding and delamination

when air gets trapped between layers

ZHU, Hong-yan, Di-hong LI, Dong-xing ZHANG, Bao-chang WU, and Yu-yong CHEN. 2009. "Influence of Voids on Interlaminar ShearStrength of carbon/epoxy Fabric Laminates." Transactions of Nonferrous Metals Society of China 19, Supplement 2 (0): s470-s475.

Center for Nondestructive Evaluation47 47

Approach: Panel Fabrication (Vacuum Bagging)

Hand laying up steps: (A) dam structure (B) Resin laying up (C) Resindistributing (D) Placing the Teflon insert at the panel mid-plane; on top offour layers (E) Placing breather (F) Placing vacuum bag and fiber and resinready to be subjected to vacuum (G) Applying vacuum bagging for 24hours (G) Panels after vacuum bagging-hard (H) Final shape of panelsafter being cured and ready to be cut.


Characterization Methods Applied

Imaging Techniques• X-ray Imaging and Laminography (BAM)• UT Volume Scans (TU Dresden and AMIC GmbH)• HF Eddy Current (IKTS)• Pulsed- and Pulsed Phase Thermography (NanoTest GmbH)• Look in Thermography (NanoTest GmbH)

Integral Characterization Methods• Thermal Conductivity (NanoTest GmbH)• X-ray Refraction (BAM)

Destructive Techniques• Serial Sectioning (Univ. Dayton)• Fatigue Test (Univ. Dayton)


ThermographyNanoTest GmbH

50 MHz UTTU Dresden

7 MHz ECIKTS

X‐ray binaryX‐ray

Comparison of Images for the Similar Coupon

BAM


X-ray Laminography 3D Reconstruction

• What we see are a lot of artifacts for instance

• Imaging techniques provide a lot of information

• Extracting the relevant information is the challenge

Result Summary & ConclusionVacuum Level

Discontinuity Contentmeasured by NDE

Bulk Thermal Conductivity W/mK

Void Volume Fraction measured by X-Ray Refraction

Mode I interlaminar

fracture toughness

(GIC) kJ/m2

Void Volume Fraction

measured by Serial

Sectioning

0 % 3.7-4.8 % 0.64 % 1.04 % 0.1 ≈4.5%

50 % 3.1-3.9 % 0.69 % 0.89 % 0.15 ≈2.5%

100 % 1.3-2.1 % 0.75 % 0.85 % 0.2 ≈2.0%

51

• In this study, instead of giving a result of discontinuity percentages in eachmethod, the parameters and features caused by discontinuity which appeared inthe results of all imaging and averaging NDE methods were correlated; forexample, thermal results correlated with ultrasonic back scattering withdensity difference by X-Ray techniques etc.

• Then, these NDE parameters and features were correlated with the mechanicaltesting performance and serial sectioning result.


Not a Summary

• NDE can provide a lot of useful (or useless) data about the structure, loading conditions, and health of a material or component.

• However, it is very unlikely that only by processing of NDE data and combining this with any kind of modelling reliable life predictions are successful, due to the complexity of design, material structure, and real world loading conditions (combines mechanical, thermal, chemical…).

• After decades of research worldwide we don’t have applicable solutions for metallic components, for composites the situation is even more complex.

• The worst case will be additive manufacturing, where uncertainties in the printing process and the resulting microstructure arise.


We need a new way of thinking in NDE

The traditional NDE philosophy:

=> One Component, One Inspector, One Instrument, Decisions based on rules and standards,will not satisfy future challenges where we theoretically print a complete aircraft.

We shall learn from medicine how to be successful in the future.


Learning from Medicine

Patient

Medical record

Patients behavior and symptoms

Medical Doctor

Decides about medical diagnostics methods

Nurses preform diagnostic non‐invasive methods Dr. makes

diagnosis and decides about treatments

Specialists analyze this data

Component

Component life record file

SHM and Con‐dition Monitoring

Technicians perform NDE measurementsDiagnosis about

continuation of use (Prognostics) or required repair

“Machine Doctor (???)” knows about NDE, material, service conditionsDecides about NDE methods

Level 3 engineers analyze this data

In Europethis is oneperson


Conclusion• Todays technology provides us with excellent measurement tools, affordable,

simple to handle, and high performance that we can access from everywhere, but we have to know what data we need and how to analyze.

• The Internet allows to use specialists worldwide to discuss results and decisions, but we have to know whom to ask.

• Powerful modeling tools make us believe that we can understand everything, but it is all based on assumptions.

• What we need to face future challenges in a world of composites, 3D printed components, smart structures and materials, and infinite data and information is a:

“Machine Doctor” who knows about the potential of NDE methods but also the materials structure and properties, design concept and service

conditions.

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